biceps

Etymology

PIE word *dwóh₁ From Latin biceps (“double-headed, two peaked”), from bis (“double”) + caput (“head”).

noun

1. (anatomy) Any muscle having two heads.
   The leg is bent by the action of the flexor muscles situated on the back of the thigh, the chief of these being called the biceps of the leg. 1901, Michael Foster, Lewis E. Shore, Physiology for Beginners, page 73
2. Specifically, the biceps brachii, the flexor of the elbow.
   The arm muscles are the show muscles of the physique. When someone asks to "see your muscles," they are most likely referring to your arms, and more specifically, your biceps. 1996, Robert Kennedy, Dwayne Hines II, Animal Arms, page 21
3. (informal) The upper arm, especially the collective muscles of the upper arm.
   Today, Stonewall's flexed biceps measure 18 inches around. 1964 Dec, “Muscles are His Business”, in Ebony, volume 20, number 2, page 147
   Biting her lip, she held his biceps for balance and waded farther. 2005, Lisa Plumley, Once Upon a Christmas, page 144
4. (prosody) A point in a metrical pattern that can be filled either with one long syllable (a longum) or two short syllables (two brevia)
   Also it is advisable to distinguish this ( ˘ ˘ ) — ˘ ˘ — rhythm, where the princeps was probably shorter in duration than the biceps (as in the dactylic hexameter), from true (marching) anapaests, in which they were equal. 1987, Martin Litchfield West, Introduction to Greek Metre
   This means that in the metrical sequence[…] recited in ordinary speech rhythm, the princeps occupied a slightly shorter time than the biceps (5:6), and if a long syllable was used to fill the biceps it had to be dragged a little[…] 2000, James I. Porter, Nietzsche and the Philology of the Future, page 347